Definition & Overview

Subdural haematoma and cysts are life-threatening conditions because they can increase the pressure on the brain or block the normal blood flow to the organ. To reduce the possibility of death due to these conditions, the haematoma or cyst must be removed from the brain. However, skull bones are tough and cannot be easily penetrated. As such, special surgical equipment are used to create holes in the skull; these are called burr holes.

The creation of burr holes is not the actual surgical procedure, but only a means to carry out whatever procedure a neurosurgeon needs to do. In this case, the procedure involves the aspiration of accumulated blood under the dura mater (subdural haematoma) or the removal of cysts.

Creating burr holes in the skull is nothing new. In fact, it is a common neurosurgical practice. The procedure is safe and has saved countless people from dying; especially those who experienced severe head injuries or trauma.

A subdural haematoma can form due to a head injury or disease. Small haematoma formations usually don’t require immediate surgery. Instead, doctors monitor the condition closely because there is a possibility that it will heal without surgical intervention.

If the surgery to remove the haematoma is required, it can be performed via a craniotomy, which is much more invasive because it involves removing a section or sections of the skull.

The procedure to create burr holes is much less invasive. In fact, it can be performed under local anaesthesia.

Who Should Undergo & Expected Results

In medicine, surgery is almost always considered as the last option, especially brain surgery. If a certain condition fails to improve on its own or with medications and non-invasive techniques, that is the only time that surgery is considered. This is because surgery is always associated with risks and complications.

The same is true with burr holes. It is important to understand that the procedure involves creating a hole in the skull. In some cases, more than one hole may be required. The skull is a tough protective cover for the brain and penetrating this cover comes with consequences.

Haematoma and cysts can be life threatening depending on their size and the severity of the condition. If a doctor recommends burr hole surgery, it likely means that the condition can no longer be treated using non-surgical approaches.

Fortunately, brain surgery has improved significantly and burr hole surgery is considered a common practice. As such, patients can expect better outcomes, especially if the neurosurgeon is highly experienced.

Burr hole surgery to aspirate a haematoma or cyst is recommended to patients who display the following symptoms:

  • Severe head pains
  • Reduced consciousness
  • Difficulty balancing
  • Changes in personality
  • Nausea or vomiting
  • Aphasia (a communication disorder characterised by the inability to comprehend and formulate language)
  • Memory loss
  • Cognitive dysfunction

Before recommending surgery, doctors perform a series of tests to determine the exact cause of the symptoms.

The risks and possibilities of complications can either be managed or prevented. If the procedure goes well and the patient doesn’t develop any complications, he or she may be discharged from the hospital after only a few days of recovery and monitoring.

How is the Procedure Performed?

The concept of burr hole surgery to aspirate subdural haematoma or cyst is relatively simple. A hole is made in the skull, the dura is opened, and the haematoma or cyst is aspirated. Once complete, the skin covering the skull is closed with sutures or staples.

Burr hole surgery can be performed as a scheduled or an emergency procedure. If it is performed as an emergency, it will likely be because the patient is already showing signs of increased cranial pressure, which is a life-threatening condition.

The patient is first prepped for surgery at the operating room. The part of the head where the burr hole is to be created is shaved and cleaned with an antiseptic. The surgery may be performed under local or general anaesthesia.

The surgeon will first create an incision in the scalp, large enough for the intended size of the burr hole. Once the skull is exposed, the surgeon will proceed to create a hole using a special drill and drill bit. The hole is created using only a small amount of pressure to ensure that the bit does not penetrate the dura mater and the brain.

Once the hole is made, the surgeon will create an incision in the dura mater and aspirate the haematoma or cyst.

Once the haematoma has been cleared or cyst has been aspirated, the scalp is closed and the patient is transferred to a recovery room for close monitoring.

Possible Risks and Complications

Although considered a safe and common procedure, there are risks and possibilities of complications associated with burr hole surgery. These include:

  • Bleeding
  • Infections
  • Leak of cerebrospinal fluid (CSF)
  • Stroke
  • Paralysis
  • Coma
  • Death

It is also possible that despite the surgeon’s best efforts, the symptoms associated with the condition will not dissipate. If this happens, the surgery may have to be repeated after a thorough analysis of the patient’s condition.


  • Northwest Brain and Spine;”Burr Hole Drainage”; Jennifer Whitlock RN;”Burr Hole Surgery Information”;

  • World Health Organization Essential Surgery Care Manual;”Cranial Burr Holes”;

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